Not if it's a hybrid transformer

http://en.wikipedia.org/wiki/Hybrid_coil

I still would bet on sufficient independant speakers being the optimal
solution.

Second best is amplitude and impedance matching the vario output
into the aux audio input of the radio (with the bonus, or drawback,
that the vario output would be muted when receiving or transmitting.
No Outputting an 8 knot climb audio signal to your struggling
competitors)

Peter

At 05:38 02 March 2015, Paul B wrote:
On Monday, 2 March 2015 15:09:04 UTC+10, Mike the Strike wrote:
The only solution I can come up with is to use transformer coupling
with
=
three windings - two input windings from the two sources and one output
win=
ding to the speaker. The windings could all be on one toroid. The only
co=
upling would be magnetic. I haven't had the energy to calculate what
value=
s might work, but offer it as a conceptual solution.
=20
Mike

Interesting thought Mike, just wondering if the current in the windings
of
=
one output would not induce current in the other windings so you still
woul=
d wind up with current backfeeding to the other amps.=20

I'll just go the conventional way for now .

Cheers

Paul